Hi Gerd, up to now I have built my UK map with the sea and land in a single pass using --generate-sea. However, some tiles are getting the sea and land inverted, typically where a very small amount of sea is in the tile. I was trying to see whether if I precompiled the sea, the problem would go away - I was assuming the tiles of precompiled sea would be bigger because they contained no other data, so the probability of inversion would be reduced. I was therefore first trying to generate precompiled sea, then use it to build my UK map. It may be that my assumption is incorrect and that it won't make any difference anyway. Regards, Mike -----Original Message----- From: Gerd Petermann [mailto:gpetermann_muenchen@hotmail.com] Sent: 29 January 2020 19:22 To: Development list for mkgmap <mkgmap-dev@lists.mkgmap.org.uk> Subject: Re: [mkgmap-dev] precompiled sea Hi Mike, not sure what you are trying to do. What do you expect to get with the last command? Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Mike Baggaley <mike@tvage.co.uk> Gesendet: Mittwoch, 29. Januar 2020 19:20 An: 'Development list for mkgmap' Betreff: [mkgmap-dev] precompiled sea Hi, I have not used precomp sea before and am struggling to compile the sea tiles. Using the following process I get a map with no sea: Used osmfilter to extract just the coastline data Used splitter on the coastline data Used mkgmap on the splitter data with a simple style that just processes coastline and with --generate-sea=multipolygon. I can see some img files created in my sea folder Used splitter again on the original data Used mkgmap again with --precomp-sea and --generate-sea=multipolygon Am I doing something wrong? Regards, Mike _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev